There are some general principles to apply when prescribing cardiovascular drugs to older people (Box). It is important to tailor a regimen for each individual patient.
Determine the goals of treatment
Prescribers should ask themselves, 'What outcome do I hope to achieve for this patient?' The prescriber should also consider what their patient hopes to achieve by following the treatment regimen. In general, cardiovascular drugs are helpful for symptom control, prevention of cardiovascular events or life extension. In a healthy 80-year-old person all three goals may be applicable. In contrast, symptom control may be the only goal for an 80-year-old with severe dementia.
In frail older people with multiple comorbidities and functional limitations, it is important to prioritise the goals of treatment. These priorities should guide prescribing. A common dilemma faced by clinicians is the combination of supine hypertension and symptomatic postural hypotension in a frail older person. In this situation, if the hypotension results in falls, dizziness and impairment of everyday function then avoiding postural hypotension should be the priority even at the expense of less than ideal control of blood pressure. High blood pressure may have to be accepted as long as it is not causing symptoms. The consequences of a fractured hip as a result of a fall due to postural hypotension can be more devastating than the vascular events one was aiming to prevent by lowering blood pressure.
Table 1 gives examples of how priorities may differ between a well older person and a frail older person for the treatment of specific cardiovascular diseases. Avoiding adverse effects is important in both groups, but the risk of harm is greater in frail older people. In addition, mortality benefits are less likely to be seen in frail older people.
Be aware of the limited evidence
Older people are poorly represented in clinical trials,1 so there are limited data about the benefit and harm of giving cardiovascular drugs to frail older patients. Clinical guidelines for cardiovascular diseases rarely provide any details on how they should apply to older frail people with multiple comorbidities. Given these limitations, prescribers should choose a regimen which is appropriate for the individual patient and minimises the risk of harm. Prescribing purely on evidence from younger patients or disease-specific guidelines leads to polypharmacy, pill burden and often harm. However, the lack of direct evidence should not be a reason to deny older people treatments that have the potential to improve their quality of life. For example, treatment to minimise the breathlessness of heart failure can have a big impact on the everyday function and overall quality of life of an older person.
Be vigilant for adverse effects
Over the past 20 years there has been an increase in hospital admissions due to adverse drug reactions particularly in people over 80 years old.2 Cardiovascular drugs are responsible for about 20% of these reactions in this age group. Adverse drug reactions can occur even at recommended adult doses. As people become frailer and acquire new diseases a previously safe and tolerated regimen may result in harm. Age-related changes in drug receptors, impairments in homeostatic mechanisms and postural autonomic function are just some of the reasons why older people are more sensitive to the hypotensive effects of many cardiovascular drugs.
Older people are likely to have diseases that result in disease–drug interactions. For example, people with dementia may become more confused if they are prescribed drugs that can cause confusion such as beta blockers. Frail older people with Parkinson's disease often have orthostatic hypotension due to disease-related autonomic dysfunction. They are therefore more likely to come to harm from hypotension when prescribed cardiovascular drugs which lower blood pressure. This problem can be exacerbated by the blood pressure lowering effects of drugs for Parkinson's disease.
In addition, older people on many different drugs (polypharmacy) are at increased risk of adverse events, in part because of the increased likelihood of drug–drug interactions.
To minimise the possibility of adverse drug reactions it is a good idea to take a 'start low, go slow' approach when prescribing. If possible, start only one new drug at a time, at the lowest dose possible and increase the dose slowly while being vigilant for possible adverse effects.
It is important to question and examine older people for possible adverse drug reactions. Often the symptoms can be non-specific such as falls, tiredness or confusion. An adverse drug reaction such as postural hypotension can easily be missed if not looked for. It is important to be aware of the common problems that could be the adverse effects of cardiovascular drugs (see Table 2). Ask specifically about, and look for, these adverse effects. Be particularly aware of drugs that have a narrow therapeutic window or a long half-life such as digoxin and warfarin.
The drug regimen should be easy to follow and, with the help of pharmacists, have packaging, labels and dose administration aids that are easy to use. A general practitioner can order a home medicine review for people living in the community. A similar scheme is funded to encourage a medication management review for patients in residential aged-care facilities.